1. Technical Field
The present invention generally relates to devices and methods for extracting tissue such as bone marrow from a patient. More particularly, the present invention relates to bone marrow aspiration needle and device.
2. Background Information
U.S. Pat. Nos. 3,628,524 and 3,598,108 disclose a device that is commonly used for tissue biopsy. In general, such devices include a cannula, in which a stylet is inserted and used to penetrate the outer layers of tissue. Once the outer layers of tissue have been penetrated, a needle is advanced to the desired depth. Then the stylet is removed and a syringe is attached to the proximal end and tissue is extracted via the needle.
Limitations exist with prior art including controlling the needle penetration depth in bone, visualization of the bone entry location and rotational movement of the cannula that could affect tissue. For example, the presence of a T-shaped handle, flange or other member that is used to brace the device may block the surgeon's view of the device in the patient thus making it more difficult to maneuver the device. Also, such devices do not include a needle, the depth of which within the patient may be adequately adjusted, relative to the cannula to accommodate the anatomy of a patient. Furthermore, rotational movement of the cannula and needle when inserted can result in damage to surrounding bone or other tissue as the needle is inserted or extracted.
These issues make it difficult to safely extract bone marrow from certain anatomical areas such as vertebrae. Bone marrow and/or concentrated bone marrow products are used in spinal fusion surgery to facilitate bone growth and healing. In such surgeries, the surgeon may prefer to extract the bone marrow from vertebrae at or near the point of surgery, rather than create a new surgical site. When extracting bone marrow from the vertebrae, conventional bone marrow extraction/aspiration needles are difficult to use and control, especially when using an anterior surgical approach. For example, if the cannula or needle rotates, tissue may be exposed to possible injury due to the needle and the cannula. In addition, due to the vertebrae anatomical limitations as compared to the ileum and the surrounding anatomy, it is desirable to have an access needle which is variable and adjustable in length so its depth within the bone can be precisely controlled.
Thus, a need exists for an adjustable depth bone marrow aspiration device that is safe, effective and able to accommodate a diverse array of clinical scenarios, including spinal surgery and/or vertebral bone marrow extraction.